Riveting machines



Jan. 13, 1970 E. CALVERT 3,489,327

RIVETING MACHINES Filed May 12, 1967 2 Sheets-Sheet 1 j FIGI.

Jan. 13, 1970 E. CALVERT 3,489,327

RIVETING MACHINES Filed May 12, 1967 2 Shmts-Sheet 2 United States Patent 3,489,327 RIVETING MACHINES Eric Calvert, Padiham, England, assignor to Joseph Lucas (Industries) Limited, Birmingham, England, a British company Filed May 12, 1967, Ser. No. 637,991 Claims priority, application Great Britain, May 13, 1966, 21,276/ 66 Int. Cl. B21j 15/28, 15/10 US. Cl. 227-1 8 Claims ABSTRACT OF THE DISCLOSURE This invention relates to riveting machines and has for its object to provide such a machine in a simple and convenient form.

A riveting machine in accordance with the invention comprises in combination, a die, a punch, actuating means for moving the die and punch relative to each other, a rivet carrier movable to a position adjacent the die, said carrier serving to locate a rivet in a position such that when the die and punch are moved relative to each other in an operative direction the rivet will be deformed between the die and the punch, and means for causing operation of said actuating means to effect relative movement of the die and carrier only when the rivet carrier has moved to a position adjacent the die.

In the accompanying drawings:

FIGURE 1 is a side elevation of one example of a riveting machine in accordance with the invention, and

FIGURE 2 is a sectional end elevation to an enlarged scale of parts of the machine shown in FIGURE 1 prior to riveting.

Referring to the drawings there is provided a body part 10 which is of generally C form so as to define upper and lower limbs 11 and 12 respectively. Secured to the limb 12 is an upstanding die 13 which is mounted in a holder, and is shaped in any suitable manner so that when a rivet is moved axially to contact the die the rivet will be deformed in the required manner. In the particular example and as shown in one clearly in FIGURE 2 the die 13 is of annular form and extending upwardly beyond the die is a pilot pin 14 which is loaded in an upward direction by a coiled compression spring 15 located within the die. The upper end face of the die is shaped to provide the required deformation of the rivet. The limb 11 carries two independently movable slides both of which are arranged to move in a vertical direction. The first slide 16 carries a punch 17 which is movable on the same axis as the die so that a rivet held intermediate the two will be operated upon. This slide is operatively connected to one end of a lever 18 which is pivotally mounted on the body part and the other end of the lever is connected to a connecting rod 19 mounted upon the crank of a crankshaft (not shown). The crankshaft is arranged to be driven through one revolution by a flywheel there being provided intermediate the flywheel and the crankshaft a clutch 20 which is operable by a first operable piston cylinder combination 21.

The second slide 22 supports a rivet carrier 23 which at its lower end extends into the path of the punch. This portion of the carrier 23 as shown in FIGURE 2, is provided with a bore through which the punch can pass during its operative or downward stroke, and prior to the operative stroke of the punch a rivet 24 is placed in said bore by any convenient rivet loading device. For moving the slide 22 a second fluid operable piston cylinder combination 25 is provided, the cylinder of which is connected to the limb 11 and the piston of which is connected to the intermediate pivot point of a toggle linkage consisting of two levers 26, 27. The lever 27 is pivotally connected to the body part whilst the lever 26 is pivotally connected to one arm of a bellcrank lever 28 which is pivotally mounted on the body part. The end of the other arm of the bellcrank lever bears against the under surface of a laterally extending stop member 29 formed on the slide 22 the arrangement being that when the bellcrank lever 28 is moved so that the end of the other arm thereof moves downwardly, the slide 22 and the rivet carrier 23 will move downwardly under the effect of gravity.

In use, the parts to be riveted such as shown in FIG- URE 2, two plates 40 having holes preformed in them are placed on the die so that the pilot 14 engages within the holes in the parts. By operation of a foot pedal (not shown) the operator admits fluid under pressure to one side of the piston of the piston cylinder combination 25 this moving the bellcrank lever as described and thereby the slide 22 and rivet carrier 23 fall under gravity to a position adjacent the die, the pilot 14 entering the lower end of the bore in the rivet carrier. When the carrier 23 has reached this position a microswitch 41 is operated by a striker 42 mounted upon the slide 22. The switch 41 when closed energises a solenoid valve 31 and fluid is admitted to the piston cylinder combination 21 and the clutch is engaged to effect an operative stroke of the punch which deforms the rivet and secures the parts together. During the downward movement of the punch the rivet is forced out of the bore in the carrier 23 and also the pilot 14 is moved against the action of the spring.

The striker 42 is adjusted so that only when the pilot 14 has entered the bore in the carrier 23 is the piston cylinder combination 21 supplied with fluid pressure to operate the clutch. In this manner the carrier 23 acts as a guard to prevent operation of the machine until it reaches the correct position. If for instance, the fingers of the operator prevent the carrier 23 falling its fullest extent then the micro switch 41 cannot be operated. After the operative stroke of the punch it is returned to its uppermost position and the slide 22 is also moved upwardly by operation of the piston cylinder combination 25. It is to be noted that the piston cylinder combination 25 does not move the slide 22 and carrier 23 downwardly in a positive manner so that if the operator has his or her fingers in the way the blow received will be that due only to the momentum gained by the slide 22 during its downward movement under the action of gravity. In order to prevent inadvertent operation of the punch the bellcrank lever 28 is provided with an extension arm 32 having a roller at its outer end which prevents movement of the lever 18 by its co-operation with a cam 33 secured to the lever 18. When the piston cylinder combination 25 is operated the roller is moved out of the paths of the cam to allow operation as described.

Having thus described my invention what I claim as new and desired to secure by Letters Patent is:

1. A riveting machine comprising in combination, a die, a punch, actuating means for moving the die and punch relative to each other, a rivet carrier movable to a position adjacent the die, said carrier serving to locate a rivet in a position such that when the die and punch are moved relative to each other in an operative direction the rivet will be deformed between the die and the punch, and means for causing operation of said actuating means to eifect relative movement of the die and punch only when the rivet carrier has moved to a position adjacent the die.

2. A riveting machine as claimed in claim 1 in which the carrier is provided with a bore through which the rivet is pushed by the punch, the carrier acting as a guard to prevent an operator inserting his or her fingers between the punch and the die whilst these are moving relatively to each other in the operative direction.

3. A riveting machine as claimed in claim 2 in which the die is provided with a spring loaded pilot which when the carrier is moved to said position adjacent said die enters said bore, the pilot being moved against the action of its spring by the rivet as the latter is forced through the bore.

4. A riveting machine as claimed in claim 3 in which said means comprises a striker mounted upon a slide sup porting said carrier, electric switch means operable by the striker when the carrie is at said position, solenoid operable valve means operable by said switch means and a piston cylinder unit for actuating said actuating means, said solenoid operable valve when operated by said switch means serving to admit fluid under pressure to said unit to cause operation of said actuating means.

5. A riveting machine as claimed in claim 4 in which said slide and carrier move under the action of gravity said release mechanism includes a fluid operable piston to said position.

6. A riveting machine as claimed in claim 5 in which cylinder combination actuated by the operator.

7. A riveting machine as claimed in claim 6 including a toggle linkage, the centre pivot of which is connected to said piston cylinder combination, and the end of one of the levers of which is pivotally connected to a fixed part of the machine, the end of the other lever being pivotally connected to one arm of a pivotal bellcrank lever the other arm of which is positioned underneath a ledge defined on said slide, the arrangement being such that when the piston cylinder combination is operated to straighten said toggle linkage said other arm of the bellcrank lever will be moved from beneath said ledge thereby allowing the slide and carrier to fall under the action of gravity.

8. A riveting machine as claimed in claim 7 including an extension arm on the bellcrank lever, a pivotal lever through which the actuating means effects movement of the punch, a cam secured to said lever and which cooperates with said extension arm to prevent movement of said pivotal lever and said punch until the bell crank lever has moved to permit the movement of the slide and carrier to said position.

References Cited UNITED STATES PATENTS 2,997,714 8/1961 Speidel 227-1 3,043,168 7/1962 May et al. 227-6l GRANVILLE Y. CUSTER, 111., Primary Examiner US. Cl. X.R. 227 

